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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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YAKDTAT BAY GLACIERS                                     27
Causes of the Existing Glaciation. The region between Cross Sound and Cook Inlet is the seat of the most extensive present-day glaciation on the North American mainland, and includes some of the largest glaciers in the world outside of the Arctic and Antarctic regions. Yakutat Bay lies near the center of this area of extensive glaciation, because it is about in the center of the lofty St. Elias Range up whose slopes the winds, which blow prevailingly from the ocean, bear their burden of vapor day after day. The unbroken mountain chain, which causes the air to rise, interposing a lofty barrier of cold, insures a heavy precipitation of snow at all seasons. At Sitka, to the southeast, the precipitation ranges from 59 to 140 inches a year; and at Nuchek, to the west, an annual precipitation of 190 inches has been recorded. The heaviest precipitation is in autumn and winter. Both of these stations are at sea level and we have no records nearer Yakutat Bay in the mountains of the St. Elias Range; we know only that the snowfall there is exceptionally heavy, under the favorable combination of an unbroken mountain barrier and prevailing onshore winds, blowing from a sea whose temperature is raised by the inflow of warm water from the south.
On all the mountains except the very lowest there are extensive snowfields, on all of them the sndwfall is heavy, and above 4000 or 5000 feet the precipitation, both summer and winter, is practically all in the form of snow. From these vast snowfields, and from others farther back in the mountains, ice tongues radiate, flooding all the valleys and filling the larger ones with vast glaciers, some of which end in the sea, others on the land at the mountain base.
General Characteristics of the Glaciers. As yet there has been no detailed study of the glaciers among the mountains back from the sea, but glimpses of portions of the region have been obtained from elevated points by various observers. The authors have looked into this snow and ice-covered mountain region from several of the low mountains near the coast, and they have had descriptions of portions of it from prospectors. The topographers of the Boundary Commission, notably A. J. Brabazon, in 1895, and the Boundary Survey parties in 1906 and 1907 in charge of Fremont Morse of the United States Coast and Geodetic Survey have seen a much wider area and have portrayed it on the maps, while some of their photographs show the condition very clearly in the snow and ice-flooded region along this part of the Alaska-Canada boundary. From a far better vantage point than either of these, upon the higher slopes of Mt. St. Elias, both Prof. I. C. Russell and the Duke of Abruzzi have looked down upon this vast sea of snow and ice. No better word picture of the supply region for the glaciers of Yakutat Bay and vicinity has been given than that of Professor Russell, which is so vivid that it deserves quotation in all descriptions of this land of glaciers. Standing upon Russell Col, on a northern shoulder near the summit of Mt. St. Elias in 1891, and looking northward, Professor Russell saw a view which he describes in the following words:
"What met my astonished gaze was a vast snow-covered region, limitless in expanse, through which hundreds and perhaps thousands of barren, angular mountain peaks projected. There was not a stream/not a lake, and not a vestige of vegetation of any kind in sight. A more desolate or more utterly lifeless land one never beheld. Vast, smooth snow surfaces without crevasses stretched away to limitless distances, broken only by jagged and angular mountain peaks. . . . The view to the north called to mind the pictures given by Arctic explorers of the borders of the great Greenland ice sheet, where